If space aliens were running away from Earth at one-sixth of the speed of light, perhaps understandably, would they bother to try to establish contact?

Bird songs and dolphins’ sounds are mentioned as real-life attempts to decipher vocalizations in non-human species. By what means do elephants and giraffes communicate? What beings use “quorum sensing” for communication?

The essay is accurate in all its calculations and its hypotheses are, at least, not impossible. And yet it is quite humorous. What does the humor consist of?